Filamentous fungus mutant strain and use thereof

Patent metadata

Field	Value
Publication number	US-10287593-B2
Application number	US-201615747923-A
Country	US
Kind code	B2
Filing date	Jul 28, 2016
Priority date	Jul 29, 2015
Publication date	May 14, 2019
Grant date	May 14, 2019

Abstract

A filamentous fungus mutant strain in which enzyme production inhibition caused by glucose is suppressed is constructed, and a method of producing a polysaccharide-degrading enzyme, a method of producing a saccharide from biomass, and a method of saccharifying biomass, each using the filamentous fungus, are provided. The filamentous fungus mutant strain in which Sre1 expression is reduced compared to a parent strain or is lost.

First claim

What is claimed is:

1. A filamentous fungus mutant strain wherein Sre1 expression is reduced compared to its parent strain or is lost, wherein the filamentous fungus is Trichoderma and wherein Sre1 is a protein selected from the group consisting of the following (a) to (c):
(a) a protein having the amino acid sequence of SEQ ID NO: 2;
(b) a protein having an amino acid sequence with an identity of 80% or more with the amino acid sequence of SEQ ID NO: 2 and having an activity as a transcription factor for genes encoding cholesterol synthesis enzymes; and
(c) a protein having the amino acid sequence of SEQ ID NO: 2 but in which one to 12 amino acids are deleted, substituted, added or inserted and having an activity as a transcription factor for genes encoding cholesterol synthesis enzymes.

2. The filamentous fungus mutant strain according to claim 1 , wherein the Sre1 expression is lost.

3. The filamentous fungus mutant strain according to claim 1 , wherein the sre1 gene is deleted or inactivated.

4. The filamentous fungus mutant strain according to claim 3 , wherein the sre1 gene comprises any of the following (d) to (i):
(d) a polynucleotide having the nucleotide sequence of SEQ ID NO: 1;
(e) a polynucleotide having a nucleotide sequence with an identity of 80% or more with the nucleotide sequence of SEQ ID NO: 1 and encoding a protein having an activity as a transcription factor for genes encoding cholesterol synthesis enzymes;
(f) a polynucleotide hybridizing to a complementary strand of the polynucleotide having the nucleotide sequence of SEQ ID NO: 1 under stringent conditions and encoding a protein having an activity as a transcription factor for genes encoding cholesterol synthesis enzymes;
(g) a polynucleotide encoding a protein having the amino acid sequence of SEQ ID NO: 2;
(h) a polynucleotide encoding a protein having the amino acid sequence of SEQ ID NO: 2 but in which one to 12 amino acids are deleted, substituted, added or inserted and having an activity as a transcription factor for genes encoding cholesterol synthesis enzymes; and
(i) a polynucleotide encoding a protein having an amino acid sequence with an identity of 80% or more with the amino acid sequence of SEQ ID NO: 2 and having an activity as a transcription factor for genes encoding cholesterol synthesis enzymes.

5. The filamentous fungus mutant strain according to claim 1 , wherein the Trichoderma is Trichoderma reesei, Trichoderma longibrachiatum, Trichoderma harzianum, Trichoderma koningii, or Trichoderma viride.

6. A method of producing a cellulase and/or a xylanase, the method comprising a step of culturing the filamentous fungus mutant strain according to claim 1 in the presence of a cellulase inducer to generate and accumulate a cellulase and/or a xylanase in a culture product and a step of collecting the cellulase and/or the xylanase from the culture product.

7. A method of producing a cellulase and/or a xylanase, the method comprising a step of culturing the filamentous fungus mutant strain according to claim 1 in the presence of a cellulase inducer and glucose to generate and accumulate a cellulase and/or a xylanase in a culture product and a step of collecting the cellulase and/or the xylanase from the culture product.

8. The method of producing a cellulase and/or a xylanase according to claim 7 , wherein the culture medium comprises the cellulase inducer in an amount of from 0.1 to 40 mass % in total and glucose in an amount of from 0.5 to 10 mass %.

9. The method of producing a cellulase and/or a xylanase according to claim 8 , wherein the mass ratio of the cellulase inducer and glucose is 10:1 to 1:1.

10. A method of producing a saccharide from biomass, the method comprising using a culture product, obtained by culturing the filamentous fungus mutant strain according to claim 1 in the presence of a cellulase inducer, as a biomass saccharifying agent.

11. A method of saccharifying biomass, the method comprising using a culture product, obtained by culturing the filamentous fungus mutant strain according to claim 1 in the presence of a cellulase inducer, as a biomass saccharifying agent.

12. The filamentous fungus mutant strain of claim 1 , wherein the Sre1 protein is a protein having the amino acid sequence of SEQ ID NO: 2.

13. The filamentous fungus mutant strain of claim 1 , wherein the Sre1 protein is a protein having an amino acid sequence with an identity of 80% or more with the amino acid sequence of SEQ ID NO: 2 and having an activity as a transcription factor for genes encoding cholesterol synthesis enzymes.

14. The filamentous fungus mutant strain of claim 1 , wherein the Sre1 protein is a protein having the amino acid sequence of SEQ ID NO: 2 but in which one to 12 amino acids are deleted, substituted, added or inserted and having an activity as a transcription factor for genes encoding cholesterol synthesis enzymes.

15. The filamentous fungus mutant strain according to claim 4 , wherein the sre1 gene is a polynucleotide having the nucleotide sequence of SEQ ID NO: 1.

16. The filamentous fungus mutant strain according to claim 4 , wherein the sre1 gene is a polynucleotide having a nucleotide sequence with an identity of 80% or more with the nucleotide sequence of SEQ ID NO: 1 and encoding a protein having an activity as a transcription factor for genes encoding cholesterol synthesis enzymes.

17. The filamentous fungus mutant strain according to claim 4 , wherein the sre1 gene is a polynucleotide hybridizing to a complementary strand of the polynucleotide having the nucleotide sequence of SEQ ID NO: 1 under stringent conditions and encoding a protein having an activity as a transcription factor for genes encoding cholesterol synthesis enzymes.

18. The filamentous fungus mutant strain according to claim 4 , wherein the sre1 gene is a polynucleotide encoding a protein having the amino acid sequence of SEQ ID NO: 2.

19. The filamentous fungus mutant strain according to claim 4 , wherein the sre1 gene is a polynucleotide encoding a protein having the amino acid sequence of SEQ ID NO: 2 but in which one to 12 amino acids are deleted, substituted, added or inserted and having an activity as a transcription factor for genes encoding cholesterol synthesis enzymes.

20. The filamentous fungus mutant strain according to claim 4 , wherein the sre1 gene is a polynucleotide encoding a protein having an amino acid sequence with an identity of 80% or more with the amino acid sequence of SEQ ID NO: 2 and having an activity as a transcription factor for genes encoding cholesterol synthesis enzymes.

Assignees

• Kao Corp

Inventors

• Arai Toshiharu
• Kakeshita Hiroshi

Classifications

• C13K1/02

  obtained by saccharification of cellulosic materials (manufacture of fodder A23K10/32) · CPC title

• C12P19/14

  produced by the action of a carbohydrase {(EC 3.2.x)}, e.g. by alpha-amylase {, e.g. by cellulase, hemicellulase} · CPC title

• C12P19/02

  Monosaccharides (2-ketogulonic acid C12P7/60) · CPC title

• C12N15/80 Primary

  for fungi · CPC title

• C12N9/2437

  Cellulases (3.2.1.4; 3.2.1.74; 3.2.1.91; 3.2.1.150) · CPC title